The demonstration of navigation safety impact is an important stage of the preliminary work of the construction of the wading project, an important measure to reduce the impact of the construction of the wading project on navigation safety, and an essential condition for the approval of the project. Navigation safety assessment is an important work before the launch of underwater activities, is a necessary link for the smooth development of underwater activities and navigation safety assurance, and is one of the main basis for the navigation safety permit of underwater activities.